http://www.mdpi.com/journal/molecules/special_issues/coumarins-and-xanthones/ {snippet name="submission_info"} http://www.mdpi.com/1420-3049/17/2/1408/ Stereoselective photodimerization of coumarin and its derivatives in supra-molecular systems is reviewed. The enantioselective photodimerization of coumarin and thiocoumarin in inclusion crystals with optically active host compounds is also described. http://www.mdpi.com/1420-3049/17/2/1408/ Fri, 03 Feb 2012 00:00:00 CET Molecules 2012-02-03 17 2 Review 1408 1418 1420-3049 Supramolecular Photodimerization of Coumarins 2012-02-03 doi: 10.3390/molecules17021408 Koichi Tanaka http://www.mdpi.com/1420-3049/16/11/9721/ The extracts of the stem bark of Calophyllum soulattri gave a new pyranocoumarin, soulamarin (1), together with five other xanthones caloxanthone B (2), caloxanthone C (3), macluraxanthone (4), trapezifolixanthone (5) and brasixanthone B (6) one common triterpene, friedelin (7), and the steroidal triterpene stigmasterol (8). The structures of these compounds were established based on spectral evidence (1D and 2D NMR). http://www.mdpi.com/1420-3049/16/11/9721/ Wed, 23 Nov 2011 00:00:00 CET Molecules 2011-11-23 16 11 Article 9721 9727 1420-3049 Soulamarin, a New Coumarin from Stem Bark of Calophyllum soulattri 2011-11-23 doi: 10.3390/molecules16119721 Gwendoline Cheng Lian Ee Siau Hui Mah Soek Sin Teh Mawardi Rahmani Rusea Go Yun Hin Taufiq-Yap http://www.mdpi.com/1420-3049/16/9/7249/ Our ongoing investigations on the stem bark of Mesua beccariana afforded a novel cyclodione coumarin, beccamarin, together with two known xanthones, mesuarianone, mesuasinone, two anthraquinones, 4-methoxy-1,3,5-trihydroxy-anthraquinone and 2,5-dihydroxy-1,3,4-trimethoxyanthraquinone and one coumarin, mammea A/AB. The structures were elucidated by 1D and 2D NMR and MS techniques. http://www.mdpi.com/1420-3049/16/9/7249/ Thu, 25 Aug 2011 00:00:00 CEST Molecules 2011-08-25 16 9 Article 7249 7255 1420-3049 A Novel Cyclodione Coumarin from the Stem Bark of Mesua beccariana 2011-08-25 doi: 10.3390/molecules16097249 Gwendoline Cheng Lian Ee Soek Sin Teh Siau Hui Mah Mawardi Rahmani Yun Hin Taufiq-Yap Khalijah Awang http://www.mdpi.com/1420-3049/14/9/3538/ The electrochemical reduction of coumarins on glassy carbon and electrodeposited metal electrodes was investigated in a Britton-Robinson buffer (pH 1.87-11.98). The effects of various factors, such as the deposition material, time, and concentration of mercury, on the precision of the analysis were explored. The possible reaction mechanism of the reduction process with regards to scan rates, peak potentials, and currents is discussed. Electroreduction was used to quantitatively determine the levels of coumarins in some essential oils and traditional Chinese herbal medicines. A comparison with high performance liquid chromatography analysis results shows good agreement. http://www.mdpi.com/1420-3049/14/9/3538/ Fri, 11 Sep 2009 00:00:00 CEST Molecules 2009-09-11 14 9 Article 3538 3550 1420-3049 Electrochemical Reduction of Coumarins at a Film-Modified Electrode and Determination of Their Levels in Essential Oils and Traditional Chinese Herbal Medicines 2009-09-11 doi: 10.3390/molecules14093538 Lai-Hao Wang Hsiu-Hua Liu http://www.mdpi.com/1420-3049/14/8/2729/ The first phytochemical investigation of the fruits of Angelica lucida has led to the isolation and characterization of five known coumarins (imperatorin, isoimperatorin, heraclenol, oxypeucedanin hydrate and heraclenin). All isolated compounds were identified by means of spectral and literature data. The extracts and the isolated constituents from A. lucida have been also evaluated for their antimicrobial activity against six Gram positive and negative bacteria, two oral pathogens and three human pathogenic fungi, exhibiting an interesting antimicrobial profile. http://www.mdpi.com/1420-3049/14/8/2729/ Mon, 27 Jul 2009 00:00:00 CEST Molecules 2009-07-27 14 8 Article 2729 2734 1420-3049 Coumarins from Angelica Lucida L. - Antibacterial Activities 2009-07-27 doi: 10.3390/molecules14082729 Jaroslaw Widelski Milena Popova Konstantia Graikou Kazimierz Glowniak Ioanna Chinou http://www.mdpi.com/1420-3049/14/7/2514/ In the present work we report on the contribution of the coumarin moiety to tyrosinase inhibition. Coumarin-resveratrol hybrids 1-8 have been resynthesized to investigate the structure-activity relationships and the IC50 values of these compounds were measured. The results showed that these compounds exhibited tyrosinase inhibitory activity. Compound 3-(3’,4’,5’-trihydroxyphenyl)-6,8-dihydroxycoumarin (8)is the most potentcompound (0.27 mM), more so than umbelliferone (0.42 mM), used as reference compound. The kinetic studies revealed that compound 8 caused non-competitive tyrosinase inhibition. http://www.mdpi.com/1420-3049/14/7/2514/ Mon, 13 Jul 2009 00:00:00 CEST Molecules 2009-07-13 14 7 Article 2514 2520 1420-3049 Tyrosinase Inhibitor Activity of Coumarin-Resveratrol Hybrids 2009-07-13 doi: 10.3390/molecules14072514 Antonella Fais Marcella Corda Benedetta Era M. Benedetta Fadda Maria Joao Matos Elias Quezada q Lourdes Santana Carmen Picciau Gianni Podda Giovanna Delogu http://www.mdpi.com/1420-3049/14/4/1546/ Six 3-methylpyridine zwitterions and six quinoline zwitterions were synthesized through the reaction of 4-hydroxycoumarins, p-benzoquinone and the corresponding N-aromatics. The novel pseudo-cyclic face-to-face rigid structure of the zwitterion was elucidated by 1H-NMR at different temperatures, and assumed to be caused by both the intramolecular ion pair attraction and the steric interaction. http://www.mdpi.com/1420-3049/14/4/1546/ Tue, 14 Apr 2009 00:00:00 CEST Molecules 2009-04-14 14 4 Article 1546 1560 1420-3049 Pseudo-cyclic Face-to-face Rigid Structure Caused by the Intramolecular Ion Pair Effect 2009-04-14 doi: 10.3390/molecules14041546 Sheng-Ling Zhang Zhi-Shu Huang Lian-Quan Gu http://www.mdpi.com/1420-3049/14/4/1495/ Several novel 4-hydroxy-chromene-2-one derivatives 2b-16b were easily prepared through condensation reactions with microwave heating and characterized by elemental analysis, IR, 1H-NMR and mass spectrometry. Geometry optimization of these compounds was executed by PM3, PM5 and Minimize Energy methods to describe them via molecular descriptors. The antimicrobial activity of the synthesized compounds was evaluated against different microbial strains using two different methods: the diffusion method and the micro-dilution method. All data indicated that the products possess antimicrobial activity which depends on the nature of substituent attached to the benzopyran moiety. In general, after 24 h the MIC values of most tested coumarins was 0.13 mg/mL, but compounds 1 and 6b displayed the strongest antimicrobial activity on the tested cultures of bacteria after 48 h. Compound 13b has the strongest growth inhibitory potential on fungus C. albicans, tested by diffusion method,with an inhibition zone of 30-37 mm at a concentration of 150 µg/mL. The conclusion of this experiment is that the synthesized compounds have varied and different influence on different classes of bacteria and the fungus C. albicans. http://www.mdpi.com/1420-3049/14/4/1495/ Tue, 14 Apr 2009 00:00:00 CEST Molecules 2009-04-14 14 4 Article 1495 1512 1420-3049 Synthesis and Molecular Descriptor Characterization of Novel 4-Hydroxy-chromene-2-one Derivatives as Antimicrobial Agents 2009-04-14 doi: 10.3390/molecules14041495 Milan Mladenović Nenad Vuković Neda Nićiforović Slobodan Sukdolak Slavica Solujić http://www.mdpi.com/1420-3049/14/3/1044/ The immobilization of some coumarin derivatives on modified poly(ethylene glycol)s is reported and the influence of the polymeric support on the photoluminescence activity of the compounds is discussed. Upon ultraviolet excitation, the derivatives showed coumarin - related emission properties whose peak position and efficiency depended on the loading of the polymer and on the mesomeric effects of the substituents. http://www.mdpi.com/1420-3049/14/3/1044/ Thu, 05 Mar 2009 00:00:00 CET Molecules 2009-03-05 14 3 Article 1044 1055 1420-3049 Evaluation of Photoluminescence Properties of Some Poly(ethylene glycol) – Supported Coumarin Derivatives 2009-03-05 doi: 10.3390/molecules14031044 Graziella Tocco Carlo Maria Carbonaro Gabriele Meli Gianni Podda http://www.mdpi.com/1420-3049/14/3/939/ We report the isolation of several coumarins and the stereochemical assessment of some pyranocoumarins, as well as the antibacterial and antioxidant activities of the three most abundant ones (grandivittin, agasyllin and aegelinol benzoate) isolated from the roots of Ferulago campestris collected in Sicily and of the hydrolysis product (aegelinol). Aegelinol and agasyllin showed antibacterial activity against nine ATCC and the same clinically isolated Gram-positive and Gram-negative bacterial strains. At a concentration between 16 and 125 mg/mL both coumarins showed a significant antibacterial effect against both Gram-negative and Gram-positive bacteria. In particular the ATCC strains Staphylococcus aureus, Salmonella thypii, Enterobacter cloacae and Enterobacter earogenes (MIC = 16 and 32 mg/mL for aegelinol and agasyllin, respectively) were the most inhibited. Antibacterial activity was also found against Helicobacter pylori: a dose-dependent inhibition was shown between 5 and 25 mg/mL. The antioxidant activity of the coumarins was evaluated by their effects on human whole blood leukocytes (WB) and on isolated polymorphonucleate (PMN) chemiluminescence (CL), PMA-stimulated and resting. http://www.mdpi.com/1420-3049/14/3/939/ Fri, 27 Feb 2009 00:00:00 CET Molecules 2009-02-27 14 3 Article 939 952 1420-3049 Antimicrobial and Antioxidant Activities of Coumarins from the Roots of Ferulago campestris (Apiaceae) 2009-02-27 doi: 10.3390/molecules14030939 Adriana Basile Sergio Sorbo Vivienne Spadaro Maurizio Bruno Antonella Maggio Nicoletta Faraone Sergio Rosselli http://www.mdpi.com/1420-3049/14/2/771/ A new O-terpenoidal coumarin 1, named hekumarone, was isolated from the leaves and twigs of Clausena anisum-olens Merr.(Rutaceae) collected in Hekou County in Yunnan Province, P. R. China. Structure elucidation and unambiguous NMR assignments for the title compound was carried out on the basis of 1D and 2D NMR experiments. http://www.mdpi.com/1420-3049/14/2/771/ Fri, 13 Feb 2009 00:00:00 CET Molecules 2009-02-13 14 2 Article 771 776 1420-3049 A New O-Terpenoidal Coumarin from Clausena anisum-olens Merr. 2009-02-13 doi: 10.3390/molecules14020771 Yun-Song Wang Hong-Yi Xu Da-Xiang Wang Jing-Hua Yang http://www.mdpi.com/1420-3049/14/1/210/ Coumarins, as a family of molecules, exhibit a wide range of fluorescence emission properties. In many cases, this fluorescence is extremely sensitive to the local environment of the molecule, especially the local polarity and microviscosity. In addition, coumarins show a wide range of size, shape, and hydrophobicity. These properties make them especially useful as fluorescent probes of heterogeneous environments, such as supramolecular host cavities, micelles, polymers and solids. This article will review the use of coumarins to probe such heterogeneous systems using fluorescence spectroscopy. http://www.mdpi.com/1420-3049/14/1/210/ Tue, 06 Jan 2009 00:00:00 CET Molecules 2009-01-06 14 1 Review 210 237 1420-3049 The Use of Coumarins as Environmentally-Sensitive Fluorescent Probes of Heterogeneous Inclusion Systems 2009-01-06 doi: 10.3390/molecules14010210 Brian D. Wagner